Question

I have two classes, namely
User & UserProfile

User contains(few attributes like):-

• userId
• loginId
• password

and
UserProfile contains(rest of all attributes like):-

• userId
• name
• address
• mobile
• dob
• email

I have two tables in the database corresponding to these classes namely User_table & User_profile_table
Now what I want is to design these classes in such a way that it accrues a perfect OOPs concept.

My question is beside the setter & getter methods what are the other methods do I need in these classes.

I planed to put a

• constructor UserProfile(Integer userId) in UserProfile class which will take userId, get the values from User_profile_table and initialize all attributes.
• another constructor UserProfile() with no parameters to initialize an object with null values.
• a saveUserProfile() to save the profile in database

I just need to work with the database like:-

For User class methods like
– saveUser()
– retriveUser()

And Similarly with the UserProfile

Shall I put the codes dealing with the database inside the saveUser and retriveUser methods?
If no then how can I handle those codes(where should I write the code dealing with the database)?

Answer 1

Some classes are value types, representing a piece of data. For these, getters and setters might be all you need.

Using getters/setters rather than public fields leaves open the possibility that you may change the representation later, without affecting callers.

Each class should have a single responsibility. If it represents a user profile, that’s all it should do. You can place additional functionality in other classes — e.g., a UserValidator.

At some point, you may become interested in object-relational mapping (ORM) tools such as hibernate and ibatis.